Carburetor with improved choke valve control



1957 J. v. REICHENBACH 3,305,223

CARBURETOR WITH IMPROVED CHOKE VALVE CONTROL Filed Sept. 50, 1965 4Sheets-Sheet l mdwgm) Joseph YREZG'ZLEUZJECZL Feb. 21, 1967 3,305,223

GARBURETOR WITH IMPROVED CHOKE VALVE CONTROL Filed Sept. 50, 1965 J, V.REICHENBACH 4 Sheets-Sheet 2 Feb. 21, 1967 J. v. REICHENBACH GARBURETORWITH IMPROVED CHOKE VALVE CONTROL Filed Sept. 50, 1965 4 Sheets-Sheet 5Feb. 21, 1967 J. v. REICHENBACH 3,305,223

CARBURETOR WITH IMPROVED CHQKE VALVE CONTROL Filed Sept. 50, 1965 4Sheets-Sheet 4 United States Patent G 3,305,223 CARBURETOR WITH IMPROVEDCHOKE VALVE CONTRQL Joseph V. Reichenbach, Miiwaukee, Wis, assignor toBriggs & Stratton Corporation, Milwaukee, Wis, a corporation of DelawareFiled Sept. 30, 1965, Ser. No. 491,519 11 Claims. (Cl. 26152) Thisinvention relates to carburetors of the type used on small, portableinternal combustion engines and re fers more particularly to a controlfor such carburetors.

Carburetors of the type with which this invention is concerned have .athrottle valve, the maximum open position of which is manuallyadjustable, and a choke valve by which the admission of air to thecarburetor may be fully or substantially interrupted during starting ofthe engine; and, as shown in the Lechtenberg et al. Patent No.3,194,224, a common manually operable control member which controls boththe throttle valve and the choke valve.

Although the manually operable control member by which the position ofthe throttle valve may be set and the choke valve closed, may beoperated directly, in many instances it i customary to provide means foractuating the control member from a remote point. This is especially soin situations where the engine drives a power lawn mower, in which eventa control lever mounted on the handle of the mower is connected to thecontrol member of the carburetor by means of a Bowden wire.

In the carburetor illustrated in the Lechtenberg et al. patent, thecontrol member is mounted to swing about a fixed axis in juxtapositionto the choke valve between an idling position in which the throttlevalve is very nearly closed, and a full throttle or high speed positionin which the throttle valve is fully open. This is the normal range ofadjustment of the control member. However, the control member is alsomovable beyond its full throttle position, and this additional range ofmotion i employed to effect closure and reopening of the choke valve. Tothis end, a finger on the control member collides with a lever fixed tothe shaft of the choke valve and imparts valve opening motion theretoagainst the bias of a spring which, in the aforesaid Lechtenberg et al.patent, at all times tends to hold the choke valve open.

Although that arrangement entailed moving the control member to itsextreme limit of motion beyond its full throttle position in order toclose the choke valve, this was not objectionable Where the controlmember was directly actuated. However, where the adjustment of thecontrol member was effected from a remote point, as by a lever locatedon the handle bars of the mower and connected with the control member bya Bowden wire, it did present problems. Unless the Bowden wire was veryaccurately adjusted and its sheath wa anchored exactly in its rightposition, it was often impossible to move the control member far enoughbeyond its full throttle position to fully close the choke valve. Theresult was difficult engine starting.

With a view toward overcoming this objection, the present invention hasas its purpose and object to provide a carburetor having an improvedcontrol or, more accurately, an improved control for carburetors andespecially the choke valves thereof, wherein complete closure of thechoke valve is assured despite the fact that the control member by whichsuch closure i effected may not have had the full range of motionimparted thereto.

More specifically, it is the purpose and object of this invention toprovide a Bowden wire type remote control for carburetors by whichcomplete closure of the choke valve will be assured, despite variationsin the extent of motion imparted to the actuator of the control by theBowden wire due to slack or inaccurate adjustment of the Bowden wire.

With a view toward achieving the aforesaid primary objectives of thisinvention, it is another object of this invention to provide acarburetor wherein the choke valve is yieldingly held either in its openor its closed position by an overcenter spring means which not onlyserves to hold the choke valve in one or the other of its positions, butalso snaps the same to each of its positions when the overcenter springmeans crosses dead center, so that both closure and opening of the chokevalve can be accomplished with a shorter actuating motion than washeretofore necessary.

Another object of this invention is to provide means whereby the chokevalve may be quickly reopened in the event it is accidentally closed, bysimply operating the control.

With the above and other objects in view which will appear as thedescription proceeds, this invention resides in the novel construction,combination and arrangement of parts substantially as hereinafterdescribed and more particularly defined by the appended claims, it beingunderstood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

The accompanying drawings illustrate one complete example of thephysical embodiment of the invention, constructed according to the bestmode so far devised for the practical application of the principlesthereof, and in which:

FIGURE 1 is a perspective view of a carburetor embodying this invention,said view illustrating -a portion of the engine supplied by thecarburetor and part of its fuel tank;

FIGURE 2 is a perspective view on a reduced scale of a power lawn mowerdriven by an engine equipped with the carburetor and control therefor ofthis invention, and illustrating the conventional way remote control ofthe carburetor is effected in such installations;

FIGURE 3 is a top plan view of the carburetor with its air cleanerremoved, illustrating the control therefor in its full throttle positionand the choke valve open;

FIGURE 4 is a view similar to FIGURE 3 but illustrating the control inits starting position, with the choke valve closed;

FIGURES 5, 6' and 7 are detail views illustrating the manner in whichthe choke valve is yieldingly held in either its open or closed positionby an overcenter spring which also serves to snap the choke valve to theposition toward which it is being moved by actuation of the control,FIGURE 5 illustrating the condition at the instant valve closing motionis being initiated, FIGURE 6 illustrating the condition directly afterthe choke valve has been moved toward its closed position far enough toenable the overcenter spring means to carry it the rest of the distancetoward closed position, and FIGURE 7 illustrating the condition justprior to reopening of the choke valve;

FIGURES 8 and 9 illustrate the manner in which operational relationshipbetween the control member and the choke valve is re-established in theevent the choke valve is accidentally closed while the engine isrunning, to enable reopening of the choke valve by actuation of thecontrol member;

FIGURE 10 is a perspective view of the control member and associatedstructure, also illustarting the manner in which operationalrelationship between the control member and the choke valve isre-established after accidental closing of the choke valve, by simplyactuating the control member;

FIGURE 11 is a detail sectional view through FIGURE 10 on the plane ofthe line 11-11;

FIGURE 12 is a detail sectional view through FIGURE 11 on the plane ofthe line 1212;

FIGURE 13 is a detail sectional view through FIGURE 3 on the plane ofthe line 13-13; and

FIGURE 14 is a fragmentary perspective view of a portion of the controlmember to illustrate a slight modification thereof.

Referring now more particularly to the accompanying drawings, thenumeral 5 designates an engine of the small, portable single cylindertype with which this invention is particularly concerned. Engines ofthis type have many uses, not least of which is the driving of powerlawn mowers, as shown for instance in FIGURE 2. When so used, the enginespeed is controlled by a lever 6 which is mounted on the handle of themower, and is connected with the carburetor of the engine through aflexible motion transmitting element or Bowden wire 7. It is alsocustomary to use this remote control to choke the engine duringstarting, and it is here where prior remote controls have led to thedifficulties which this invention overcomes. The manner in which this isaccomplished will be presently described, but first the general natureof the carburetor and its control must be understood.

The carburetor, indicated generally by the numeral 8, may be like thatof the aforesaid Lechtenberg et al. Patent No. 3,194,224. Hence, it hasa tubular body portion 9 provided with a mixture passage 10 which leadsto the intake port of the engine and has an upwardly facing air inlet 11to receive air through an appropriate air cleaner 12. The carburetor issecured to the top wall of a fuel tank 13, which in turn is solidlysupported from the engine by means including a bracket 14 fixed to theengine in any suitable way, and substantially coplanar with an end wall15' of the customary air directing shroud 15 of the engine.

The carburetor has a throttle valve 16 mounted in its mixture passage,to swing between open and closed positions, and a choke valve 17 whichcontrols the admission of air to the carburetor. A common control,indicated generally by the numeral 18, is provided for both of thesevalves, and this common control includes a movaable control member 19which is pivoted, as at 21), to a horizontal flange 21 forming part ofthe bracket 14. A tension Spring 22 connects the movable control member19 with the throttle valve and the actuating arm 23 of a governor (notshown). It is possible, therefore, to set the maximum speed at which theengine is to run by adjusting the position of the control member;movement thereof in one direction increasing the tension on the springand causing the throttle valve to open, while opposite adjustment of thecontrol member decreases the spring tension and causes the engine to runslower.

The manner in which the governor maintains the selected engine speedforms no part of this invention, and hence has not been illustrated.

During operation of the engine, the normal range of motion or adjustmentof the control member 19 is between full throttle and idling positions.These positions are identified by detents in the form of indentations 24and 25 in the flange 21 and a downwardly projecting pimple 26 in thebase portion 27 of the control member. As the control member is rotatedabout its pivotal mounting 20, the pimple 26 travels in an are whichintersects the indentations, to snap into one or the other when thecontrol member reaches its full throttle or idling position, the fullthrottle position which is shown in FIGURE 3, being identified byengagement of the pimple into the indentation 24.

As in the carburetor of the Lechtenberg et al. patent, the controlmember may be moved beyond its full throttle and idling positions.Movement of the control member beyond its idling position defined by theindentation 25 carries it to a stop position in which it grounds theignition circuit, but since this latter feature is in nowise involved inthe present invention, it has not been illustrated.

On the other hand, the movement of the control member beyond its fullthrottle position is significant to the present invention, since it isthis additional motion of the control member which is employed to effectclosure and reopening of the choke valve in a manner now about to bedescribed.

The choke valve 17 is of the customary butterfly type, and preferably isconstructed and mounted as in the aforesaid Lechtenberg et al. patent.Accordingly, the choke valve is fixed to a shaft 28 which is journalledin an appropriately located bearing formed in the carburetor body, andis part of a plastic molding. On its outer end, the shaft 28 has a lever29 formed integrally therewith, to provide means by which the chokevalve may be swung from one position to the other. The outer end portionof the lever 29 is bifurcated, the resulting bifurcations 30 and 31being respectively long and short.

The choke valve is yieldingly held in either its open or closed positionby yieldable overcenter means, indicated generally by the numeral 32,and comprising a tension spring 33, an anchor 34 for one end of thespring fixed with respect to the carburetor body, and a connection 35between the other end of the spring and the bifurcated lever 29. Theanchor 34 is so located with respect to the axis about which the chokevalve swings, that in the open position of the valve (see FIGURE 5), theconnection 35 between the spring and the bifurcated lever 29 is at oneside of the choke valve axis, while in the closed position of the chokevalve (see FIGURE 7), the connection 35 between the spring and thebifurcated lever is at the other side of the valve axis. Obviously,therefore, the overcenter means crosses dead center at an intermediateposition of the choke valve, and acts to yieldingly hold the valve inthe position towards which it is moving when dead center is crossed.

As noted hereinbefore, the choke valve is moved from one positionthereof towards the other by rotation of the control member 19 about itspivotal mounting 20, between its full throttle position and its extremeposition of clockwise rotation beyond full throttle. T 0 enable thecontrol member to perform this function, it has an actuating finger 39formed integrally therewith, to travel in a defined arcuate path whichintersects the bifurcated lever 29. Normally, this path of motion of thefinger 39 lies in a horizontal plane parallel to the flange 21 and abovethe axis of the choke valve.

When the choke valve is open, as shown in FIGURES 1, 3 and -5, the longbifurcation 30 occupies a substantially vertical position directly inthe path of the finger 39 as the latter travels in a clockwisedirection, as viewed from the top, during motion of the control memberfrom its full throttle position toward its extreme limit of clockwiserotation. The special relationship of the parts is such that contact ismade between the finger 39 and the long bifurcation 30 as the controlmember leaves its full throttle position. Thus, upon continued motion ofthe control member in a clockwise direction beyond its full throttleposition, the bifurcated lever will be rocked in the direction to closethe choke valve. As it does, the overcenter means 32 crosses deadcenter, so that the tension of its spring 33 snaps the choke valve toits closed position long before the control member reaches its extremelimit of choke valve closing clockwise rotation.

This is one of the most significant features of the instant invention.Because of it, full closure of the choke valve is assured, regardless ofwhether or not the control member has been moved to its extreme limit ofchoke valve closing motion, which was not the case with prior carburetorcontrols. The advantage gained by this feature of the invention isespecially significant in situations requiring remote control of thecarburetor as in the power lawn mower shown in FIGURE 2. Now, for thefirst time, lack of absolutely accurate adjustment of the Bowden wiredriving connection between the control lever 6 on the mower handle andthe movable control member 19, does not prevent full closure of thechoke valve. As a result, it is not too important just where the sheathof the Bowden wire is anchored, it being sufiicient that the lower endthereof be secured in any suitable manner to a fixed portion of theengine, as by means of a clamp 44 secured to the end wall of the shroud15, and that the upper end of the sheath be secured to the mower handlein any suitable way.

As best seen in FIGURES 5, 6 and 7, the bifurcations and 31 are spacedapart a distance substantially greater than the width of the actuatingfinger 39. Accordingly, the bifurcations and the finger 39 may beconsidered a lost motion driving connection between the control memberand the choke valve.

As also shown in FIGURES 5, 6 and 7, when the choke valve is snapped toits closed position by the overcenter spring means, the inner edge ofthe short bifurcation 31 moves into the path of the finger 39 so that,during retrograde or counterclockwise rotation of the control member,the finger collides with the short bifurcation and imparts choke valveopening torque to the bifurcated lever. To facilitate this action, theinner edge 45 of the short bifurcation presents a downwardly facinginclined cam surface to the approaching finger 39 when the choke valveis in its closed position.

As the bifurcated lever is lifted by the advancing finger 39 and thechoke valve begins to open, the overcenter spring means is carriedtoward dead center and the instant it crosses dead center it acts tosnap the choke valve to its open position, and with this action, theshort bifurcation 31 swings out of or below the path of the finger 39,so that continued motion of the control member toward its idlingposition is possible.

- Inasmuch as the finger 39 moves away from the bifurcated lever 29 whenthe choke valve is opened and the control member is brought to aposition somewhere along its range of motion between full throttle andidling, and since the choke valve is held open only by the overcenterspring means, the choke valve can be accidentally closed-as, forinstance, by 'a twig on a bush coming in contact therewith as the moweris operated in its vicinity. Such accidental closure of the choke valvewhile the engine is running will, of course, interfere with properengine operation and will call for prompt reopening of the valve.

Since many users of engines of this type, for instance, the ordinaryhome owner, seldom recognize what has happened when an accidentallyclosed choke valve suddenly causes the engine to lose speed and giveevery indication of stopping, an operator, by instinct, will work thecontrol lever back and forth. In recognition of this fact, the presentinvention provides means whereby such back and fort-h actuation of thecontrol member will reopen the accidentally closed choke valve.

As shown in FIGURES 8-11, when the choke valve is accidentally closedthe bifurcated lever 29 assumes a position at which the outer edge 46 ofits short bifurcation lies across the path of the finger 39. Thus, asthe finger moves along its path with return of the control membertowards its full throttle position, it collides with the edge 46. But toenable the actuating finger 39 to be brought into proper operationalrelationship with the bifurcated lever and permit reopening of the chokevalve by the instinctive back and forth actuation of the control member,it must be possible for the finger 39 to ride over the short bifurcation31. To enable this to occur, yieldability is incorporated in theengagement which occurs between the finger and the outer edge of theshort bifurcation as the control member is moved towards its fullthrottle position. This yieldability is obtained in either of two ways,or preferably by a combination thereof.

The needed yieldability can be obtained by forming the bifurcated leverof material having a high degree of inherent resilience-as, forinstance, nylon-and by joining the short bifurcation to the rest of thelever through a reduced neck portion. It can also be accomplished byincorporating yieldability in the mounting of the control member whichpermits it to tilt, as shown in FIGURES 10 and 11, as the finger ridesup onto the outer edge of the short bifurcation. In any event, as thecontrol member is moved back toward its full throttle position, thefinger rides up onto the short bifurcation and drops oil? the endthereof into the space between the bifurcations so that, movement of thecontrol member in the opposite direction reopens the choke valve. Tofacilitate the finger riding across the short bifurcation, its outer endportion 39' is twisted to present a smooth surface to the outer edge 40of the short bifurcation.

Yieldability in the mounting of the control member is afforded byinterposing a spring washer 50 of the Belleville type between the topface of the control member and the head 51 of the rivet which providesthe pivotal mounting 20 for the control member. Ordinarily, the springwasher holds the control member in fiat parallel relationship with thetop face of the mounting bracket flange 21, but when the finger 39 ridesup onto the outer edge 46 of the short bifurcation, the spring yieldsand allows the finger to ride up over the short bifurcation and into thespace between the bifurcations.

For engines that are destined to be used with implements and equipmentrequiring remote control of the carburetor, such as the lawn mower shownin FIGURE 2, it is preferable to incorporate the spring in the pivotalmounting of the control member, even though the bifurcated lever ismolded of inherently resilient material; but where the control member isto be directly manually actuated, as in the case of riding type mowerswhere the engine usually is directly beneath the operator, it ispreferable to rely solely upon the inherent resilience of the materialof which the bifurcated lever is formed and to omit the spring from themounting of the control member. This provides greater frictionalresistance to unwanted creeping of the control member from an adjustedposition. Also, for such direct manual adjustment, the control membermay be equipped with a handle 55, as shown in FIGURE 14 and this handlemay be provided with means for attaching a Bowden wire thereto, asindicated in dotted lines.

Since some delay in actuation of the control member to reopen the chokevalve after the engine has started is inevitable, and since theadmission of some air is necessary to keep the engine running, the chokevalve has an air admission port 60 which is normally closed by a suctionresponsive valve 62. This valve is simply a poppet held in its closedposition by a light spring 63, with the head of the valve at that sideof the choke valve which faces inwardly when the valve is closed so thatit will be drawn off its seat by engine suction.

From the foregoing description, taken in connection with theaccompanying drawings, it should be apparent to those skilled in thisart that this invention eliminates one of the chief causes of difiicultengine starting by assuring full closure of the choke valve when thecarburetor control is actuated to its choke or engine starting position.

What is claimed as my invention is:

1. A control for the choke valve of a carburetor by which the valve maybe manually opened and closed from a point remote from the carburetor,said control comprising:

(A) a control member mounted for back and forth movement between definedlimits along a path fixed with respect to and adjacent to the chokevalve;

(B) a flexible driving member connected to the control member and bywhich said member may be moved from a point remote therefrom;

(C) cooperating transiently engageable abutment means fixed with respectto the control member and the choke valve, providing a lost motiondriving connection through which movement of the control member canimpart movement to the choke valve from one position thereof towards itsother position while leaving the choke valve free to continue its motionto such other position without hindrance from the control member; and

(D) overcenter drive means including a spring,

said overcenter drive means being connected with the choke valve toyieldingly hold the same in either its open or closed position and tosnap the same to the position toward which it may be moving inconsequence of motion being imparted thereto by the control member whensaid overcenter drive means crosses dead center, so that closure of thechoke valve takes place before the control member reaches the limit ofits motion in the direction it must be moved to elfect closure of thechoke valve, whereby normal variations in the amount of motion impartedto the control member by the flexible driving member due to slack in thelatter and other causes, do not interfere with full closure of the chokevalve.

8 with the finger during return motion of the control member to effectmovement of the choke valve towards its open position.

4. The control of claim 3, wherein said bifurcations are of differentlengths and the long bifurcation is the one which has engagement withthe finger during movement of the control member to effect closure ofthe choke valve,

wherein the short bifurcation occupies a position out of the path of thefinger when the choke valve is in its open position,

wherein the valve actuating engagement between the finger and the shortbifurcation and the consequent movement of the short bifurcation out ofthe path of the finger occurs before the control member reaches thelimit of its motion in the direction it moves to effect opening of thechoke valve, so that accidental closure of the choke valve and re-entryof the short bifurcation into the path of the finger is possible withouthindrance from the control member when the latter has moved beyond thepoint at which valve actuating engagement occurs between the finger andthe short bifurcation,

and further characterized by means providing yieldability in theengagement between 2. A control for the choke valve of a carburetor bywhich the valve may be manually opened and closed either from a pointremote from the carburetor or directly the finger and the ShortIblthreatleh durlhg movement at the carburetor, said control comprising:of the control member in the valve closing direction (A) a trol member td f b k d f h while the valve is closed, so that the shortbifurcamovement between defined limits along a path fixed tioh and thefinger y be restored to Valve Opening with respect t d dj t t th h k lrelationship and the accidentally closed valve may said control memberbeing operable either by dibe reopened y means of the Control member.

rect manual actuation thereof or by a flexible The Control Of elaifhwherein: driving member connected thereto and operable Said finger is Onthe Control member a m s at a remote point; therewith;

(B) cooperating transiently engageable b t t (B) the lever is fixed withrespect to the choke valve; means fixed with respect to the controlmember and the bithfeatiohs 0n the l r are f different the choke valve,providing a lost motion driving lengths, connection through whichmovement of the control the inner edge of the long bifurcation is membercan impart movement to the choke valve gaged y the finger duringmovement of the from one position thereof towards its other positionControl member t0 ff ct Closure Of the choke while leaving the chokevalve free to continue its Valve, motion to such other position withouthindrance the inner g of the Short bifurcation is from the ont ol m ber;d gaged by the finger during movement of the (C) overcenter drive meansincluding a pring, control member to effect opening Of the choke saidovercenter drive means being connected with Valve, and

the choke valve to yieldingly hold the same in the Short bifurcationmoves Out of the P either its open or closed position and to snap 0f thefinger as the 0vefeehter means Shape the the same to the position towardwhich it may be eheke valve to its p Position;

moving in consequence of motion being im- Valve actuating engagementbetween the finger parted th t by th t l member h and the shortbifurcation and consequent movement said overcenter drive means crossesdead center, 0f the Short bifurcation Out Of the P of the fihgel' so tht l u f h h k valve takes place occurs before the control member reachesthe limit befor th o t ol member r he th li i of of its motion in thedirection it moves to effect openit oti i th di ti it t h moved to ingof the choke valve, so that accidental closure of eifeet closure f th hk l h b the choke valve and re-entry of the short bifurcation malvariations in the amount of motion iminto the path of the finger ispossible without hinparted to th o tr l member d t interfere drance fromthe control member when the latter has with f ll lo ur of th hok v lmoved beyond the point at which it effects opening 3. The control of clim 2, wher i th oo ti of the choke valve, such accidental closure of theabutment means which provides the lost motion driving Choke Valve and y0f the Short bifurcation connection between the control member and thechoke into the P Of the finger disrupting P P p tional relationshipbetween the finger and the bifurcated lever and placing the outer edgeof the short bifurcation in position to have the finger collidetherewith as the control member is moved in its valve closing direction,and said control being further characterized by (E) means for restoringproper operational relationship between the finger and the bifurcatedlever by movement of the control member, said means comvalve comprises afinger constrained to move along a defined path,

a lever oscillatable about a fixed axis, and

bifurcations on the free end portion of the lever,

one of said bifurcations extending across the path of the finger whenthe choke valve is in its closed position to have valve actuatingengagement with the finger during movement of the control member in thedirection to effect movement of the choke valve towards its closedposiprising h d (l) yieldable means maintaining the finger and the otherof said bifurcations being moved into the outer edge of the shortbifurcation on a the path of the finger concomitantly with clocollisionpath when the choke valve has been sure of the choke valve, so that saidother biaccidentally closed; and

furcation will have valve actuating engagement (2) coacting means on theouter edge of the short bifurcation and the finger enabling the fingerto ride over the short bifurcation and into the space between thebifurcations.

6. The control of claim 5, wherein said yieldable means is provided byinherent resilience in the short bifurcation and its junction with therest of the lever.

7. The control of claim 5, wherein said yieldable means is provided by aspring incorporated in the mounting of the actuating lever.

8. The control of claim 5, wherein said lever is formed of materialhaving a substantial degree of inherent resilience so that the shortbifurcation may be deflected out p of its normal position, and whereinthe mounting of the control member incorporates a spring which permitsdeflection of the finger on the control member as it rides up onto theouter edge of the short bifurcation, said inherent resilience and thespring coacting to provide said yieldable means.

9. In a carburetor having a throttle control member mounted for movementfrom an idling to a full throttle position and also beyond the fullthrottle position, and having a choke valve constrained to swingabout afixed axis between open and closed positions in consequence of movementof said control member between said full throttle position and anextreme position therebeyond:

(A) a finger on the control member movable along a defined path withsaid member;

(B) a lever fixed with respect to the choke valve to swing about saidfixed axis,

said lever having bifurcations on its free end portion, one of whichextends across the path of said finger when the choke valve is in itsopen position to be engaged by the finger during movement of the controlmember toward said extreme position to effect closure of the chokevalve, and the other of said bifurcations being moved into the path ofsaid finger concomitantly with closure of the choke valve, so that thefinger will engage the same and effect reopening of the choke valveduring return motion of the control member toward its full throttleposition; and

(C) overcenter spring means operatively connected with the choke valveto yieldingly hold the same in either its open or closed position and tosnap the same to each of said positions when the overcenter spring meanscrosses a dead center position which is reached before the controlmember is advanced to said extreme position thereof or returned to itsfull throttle position, so that closure of the choke valve is notdependent upon the control member reaching its said extreme position.10. In a carburetor, the structure set forth in claim 9, wherein thebifurcation which is engaged by the finger during opening of the chokevalve swings out of the path of the finger as the valve snaps to itsopen position, but occupies a position with the outer edge thereof inthe path of the finger in the event of accidental closure of the chokevalve after the valve has been opened, and further characterized bymeans for enabling reopening of the accidentally closed choke valve byactuation of the control member, said means comprising means yieldinglymaintaining the finger and said outer edge of the bifurcation on acollision course as the control member is moved to carry the fingertowards the bifurcated lever while the valve is open, and

coacting cam means on the outer edge of said bifurcation and the fingerto cause the finger to ride over the bifurcation and into the spacebetween the bifurcations.

11. In a carburetor, the structure of claim 9, further characterized byan air admission port through the choke valve, and a suction responsivevalve normally closing said port, said valve opening in response toengine produced suction to permit a limited amount of air to pass intothe carburetor until the choke valve is opened.

References Cited by the Examiner UNITED STATES PATENTS 2,017,890 10/1935Bracke 26l64 X 2,065,167 12/1936 Wirth et al. 261--64 2,892,612 6/1959Georgiefi" 251-280 X 3,194,224 6/1965 Lechtenberg et al. 261-64 X HARRYB. THORNTON, Primary Examiner. T. R. MILES, Assistant Examiner.

1. A CONTROL FOR THE CHOKE VALVE OF A CARBURETOR BY WHICH THE VALVE MAYBE MANUALLY OPENED AND CLOSED FROM A POINT REMOTE FROM THE CARBURETOR,SAID CONTROL COMPRISING: (A) A CONTROL MEMBER MOUNTED FOR BACK AND FORTHMOVEMENT BETWEEN DEFINED LIMITS ALONG A PATH FIXED WITH RESPECT TO ANDADJACENT TO THE CHOKE VALVE; (B) A FLEXIBLE DRIVING MEMBER CONNECTED TOTHE CONTROL MEMBER AND BY WHICH SAID MEMBER MAY BE MOVED FROM A POINTREMOTE THEREFROM; (C) COOPERATING TRANSIENTLY ENGAGEABLE ABUTMENT MEANSFIXED WITH RESPECT TO THE CONTROL MEMBER AND THE CHOKE VALVE, PROVIDINGA LOST MOTION DRIVING CONNECTION THROUGH WHICH MOVEMENT OF THE CONTROLMEMBER CAN IMPART MOVEMENT TO THE CHOKE VALVE FROM ONE POSITION THEREOFTOWARDS ITS OTHER POSITION WHILE LEAVING THE CHOKE VALVE FREE TOCONTINUE ITS MOTION TO SUCH OTHER POSITION WITHOUT HINDRANCE FROM THECONTROL MEMBER; AND (D) OVERCENTER DRIVE MEANS INCLUDING A SPRING, SAIDOVERCENTER DRIVE MEANS BEING CONNECTED WITH THE CHOKE VALVE TOYIELDINGLY HOLD THE SAME IN EITHER ITS OPEN OR CLOSED POSITION AND TOSNAP